1. Field of the Disclosure
The disclosure generally relates to a hard mask composition and a method for manufacturing a semiconductor device using the composition.
2. Brief Description of Related Technology
As the fields of application of semiconductor devices have expanded, there has been a need to manufacture a memory device of high capacity with improved integrity. Semiconductor manufacturing processes necessarily include a lithography process for forming a line pattern (such as a gate line and a bit line), or a contact hole pattern (such as a bit line contact).
In order to form a critical dimension (CD) below 0.07 μm, the lithography process has been developed with Deep Ultra Violet (DUV) light sources of short wavelength such as ArF (193 nm) or VUV (157 nm) instead of long wavelength light sources such as I-line or KrF (248 nm).
Generally, the lithography process includes a process for forming a bottom anti-reflection layer in the bottom of the photoresist film so as to prevent scattered reflection from a bottom layer of a photoresist film and remove standing waves resulting from thickness variation of a photoresist film.
On the other hand, the thickness of photoresist layers also becomes smaller to prevent photoresist patterns from collapsing during the lithography process. As a result, it is difficult to secure an etching selectivity of a photoresist pattern as an etching mask on an underlying layer during the etching process.
In order to secure the etching selectivity, a multi-layer hard mask film having the etching rate relatively higher than that of the photoresist pattern is formed between the underlying layer and the photoresist pattern in the conventional method for manufacturing a semiconductor device. For example, the above-described conventional method includes forming a multi-layer hard mask film including an amorphous carbon film 3 and insulating film 5 on an underlying layer 1 over a semiconductor substrate, and then sequentially forming an anti-reflection film 7 and a photoresist pattern 9 (see FIG. 1).
Consequently, films that serve as the organic anti-reflection layer and the hard mask film are required to simplify the process.
A conventional composition for the organic anti-reflection layer satisfies the following conditions.
First, while an anti-reflection layer is coated and then a photoresist layer is coated, the anti-reflection layer should not be dissolved by an organic solvent in a photoresist composition. Thus, the anti-reflection layer is designed to have a cross-linking structure in a process for coating an anti-reflection layer composition and baking the composition to deposit the anti-reflection layer. Here, other chemical materials should not be generated as by-products.
Second, the composition is required to contain a material having a high light absorbance to light sources to inhibit scattered reflection from a bottom layer.
Third, the composition is required to contain a catalyst for activating the cross-linking reaction in the process for depositing the anti-reflection composition.
Moreover, a film used as the hard mask film is required to have the excellent etching selectivity to the bottom-underlying layer.